ICICI Bank, the country's second-largest private sector lender, said on Wednesday that it will institute a probe by an independent person against its chief executive Chanda Kochhar in connection with allegations made by an anonymous whistleblower.

In a stock exchange filing, ICICI Bank said the complainant had alleged that Kochhar had “not adhered to” provisions relating to the bank's code of conduct thereby leading to “conflict of interest”, apart from alleging “quid pro quo.”

The bank is battling allegations that Kochhar allegedly favoured Videocon Group in its lending practices. Videocon’s founders, led by Venugopal Dhoot, had an investment in a renewable energy company founded by Kochhar’s husband Deepak.

Deepak’s brother Rajiv Kochhar is also under the scanner in the matter.

The bank’s board had in April given Kochhar a clean chit in the matter. The Central Bureau of Investigation (CBI) had earlier instituted a preliminary enquiry and begun investigating the matter, nearly two years after an anonymous shareholder had raised questions.

Although the bank’s stock exchange filing on Wednesday does not explain what prompted the change in the board’s stance, a senior executive who did not wish to be named said that the complaint on the basis of which the new probe has been instituted “would have come up in the last 7-10 days.”

“There was a board meeting on 7 May, to announce [earnings] results, and then there was another board meeting on 29 May. It is my understanding that the complaint would have come between these two dates,” this person said, without divulging further details

This person also did not confirm whether the latest complaint was the same as the one on which the CBI had acted.

The Indian Express newspaper had first reported in March this year that law enforcement agencies were investigating a web of transactions involving Deepak, Chanda, her bank and Venugopal Dhoot, the promoter of the Videocon Group.

It then detailed how in December 2008, Deepak, along with two relatives, set up NuPower with Dhoot, who then gave the company a Rs 64 crore loan through a fully-owned entity, before transferring the company’s ownership to a trust headed by Deepak, for just Rs 9 lakh.

This transaction raised issues of conflict of interest, nepotism and quid pro quo, as just six months ago, Dhoot had received a Rs 3,250 crore loan from ICICI Bank, of which Rs 2,810 crore remains unpaid. Moreover, last year, the Videocon account was declared a non-performing asset.

ICICI Bank, on its part, had denied doing any favour to Dhoot or his company and said it had replied to all the questions raised by regulators. Videocon, too, has denied any wrongdoing.

On Wednesday, ICICI Bank’s shares on the BSE ended down 1.69% to close at Rs 285 apiece. The stock had lost as much as 15% after the allegations in late March through April, before recovering around 13%.

The stock is down more than 20% from the peak of Rs 365.6 apiece in January this year.